1. Field of the Invention
The present invention relates to a method and apparatus for holding cameras used for stereoscopic viewing of a patient's body cavity.
2. Description of the Prior Art
Endoscopes have commonly been utilized in surgery to enable the surgeon to view the body cavity through relatively small incisions thereby minimizing trauma and post operative pain and recovery.
Conventional endoscopes typically provide for viewing the internal organs in the form of a planar object without a three dimensional view thus limiting the effectiveness, efficiency and convenience for the surgeon in achieving the objective of the operation. The advantages attendant stereoscopic viewing of a patient's internal organs through a small incision have long been known. The recognition of these advantages have led to the development of various sophisticated methods and equipment in effort to devise an endoscopic probe for insertion through a small incision into a body cavity to enable the surgeon to view the surgery by three dimensional television. However, the devices proposed for such endoscopic systems are typically technically sophisticated requiring significant development costs and capital investment beyond the financial capability of many of the present day medical institutions. Thus, surgeons on the staff of the majority of such institutions are currently left without the capability of performing endoscopic surgery with the benefit of stereoscopic observation of the surgery site.
Substantial work has been performed in the field. It has been proposed to provide a binocular endoscope housed in a tube combined with a conduit for irrigation and including a gear mechanism for rotating an optical shaft within the tube. A device of this type is shown in U.S. Pat. No. 4,061,135 to Widran. The system disclosed is rather sophisticated, expensive and fails to incorporate video cameras and monitors enabling effective use of existing non-stereoscopic endoscopes in any combination which will achieve a perspective view of the surgical site.
It has been proposed to provide a custom made stereoscopic endoscope housed in a sheath bundling a pair of image guides, a light guide and various other channels for air, water, gas or other liquids. A device of this type is shown in U.S. Pat. No. 4,651,201 to Schoolman. While recognizing the advantages of stereoscopic endoscopes, the devices described is relatively complicated, cumbersome, expensive to manufacture and inconvenient to use.
It has also been proposed to provide a arthroscope for viewing of human or animal joints which includes a prism arrangement in effort to achieve stereoscopic capability. A device of this type is shown in U.S. Pat. No. 4,924,853 to Jones. A device of this type requires relatively sophisticated technology and is expensive to manufacture.
Other efforts to provide a stereoscope endoscope device includes the proposal of a pair of flexible endoscopes incorporated in a pair of fiber optical systems to be viewed through oculars. A device of this type is shown in U.S. Pat. No. 3,520,587 to Tasaki. While providing certain benefits, such a device suffers the shortcoming that it is expensive to manufacture and compromises the advantages of rigidity in endoscopes for manipulation in a body cavity.
Other efforts to achieve stereoscopic viewing of internal organs includes the provision of a sophisticated flashing strobe lamp with a synchronized rotating prism as shown in U.S. Pat. No. 4,862,873 to Yajima and an electronic endoscopic device as shown in U.S. Pat. No. 4,926,257 to Miyazaki.
Efforts to stereoscopically view a surgical procedure has led to a proposal of an orbiting fixture indexed to a patient's skull to mount a micro manipulator in fixed relation to the skull with a pair of converging tubes for telescopical receipt of endoscopes to converge together within a distal barrel configured at its distal end with flexible expander fingers to maintain the tissue to be examined spaced from the ends of the endoscopes. A device of this type is shown in U.S. Pat. No. 4,386,602 to Sheldon. Devices of this type, while satisfactory for the precision work required for cranial access, suffer the shortcoming that they are expensive to manufacture and require some degree of expertise to make effective use thereof and are time consuming to set up and use. Moreover, such devices leave the distal ends of the endoscope and associated cameras supported only in cantilever fashion, without fixing the cameras in spaced relation to one another. This then will often result in relative movement between the cameras thus tending to cause relative movement between the endoscopes and consequent relative movement between the images displayed on a monitor thereby contributing to the challenge of performing the surgical procedure in an efficient and safe manner.
The general thinking of current day manufacturers of stereoscopic thoracoscopes aims at miniaturization for introduction of a probe through a single small incision. Manufacturers such as Zeiss and Baxter have proposed such thoracoscopic systems and, when FDA approval is achieved, each such system may well require a capital investment of $40,000.00 to $50,000.00. Thus, there exists a need for a practical and inexpensive stereoscopic endoscopic apparatus which will make the benefits of stereoscopic viewing available to a wider range of medical institutions and to surgeons practicing in less affluent geographic areas.
In my U.S. Pat. No. 5,475,519, issued Dec. 12, 1994, I disclosed a holder for holding monoscopic endoscopes connected with respective cameras for viewing of a surgical procedures. While satisfactory for its intended purpose, I have discovered that performance of that apparatus can be improved by providing a fixture for holding the cameras in fixed relation to one another to thereby provide stability against relative movement during the procedure.
Other objects and features of the invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawing.